# 第一种实现方法
tar = [1, 2, 3, 4]
count = 0
for i in range(len(tar)):
    t1 = tar.copy()
    x = str(t1.pop(i))
    for j in range(len(t1)):
        t2 = t1.copy()
        y = str(t2.pop(j))
        for k in range(len(t2)):
            print(x + y + str(t2[k]), end='  ')
            count += 1
    print('')
print('最终结果为：%s个' % count)

